cosmos



I 15 1956 w. J. cosmos Re. 24,152 I CONTACT WHEEL ori inal Filed on 2 1o 6 .R. r0 w w v r II/k Z 4 m v 0 R 9 L CONTACT WHEEL William J. Cosmos,Highland Park, 111., asslgnor to Chicago Rubber Company, Inc., acorporation of Illinois Original No. 2,639,560, dated May 26, 1953,Serial No.

187,851, October 2, 1950. Application for reissue March 17, 1955, SerialNo. 495,079

2 Claims. (Cl. 51-141) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by r'ei'ssue.

This invention relates to contact wheels for grinding, burnishing,butting-polishing and similar purposes.

It provides a contact wheel which is not only cheaper i ice circulargrooves 16, less deeply recessed into the metal, which may have forinstance, triangular contour;

The flange '12 is perforated by a series of small drill holes 17extending into and through the flange, parallel with one another andwith the large central or axial hole 18. The central hole 18 receivesthe shaft (not shown), as usual. The peripheral holes '17 whichareparallel s with the axis, that is, longitudinal withrespect to thebut at the same timestronger, quieter, steadier and cooler than-wereltheearlier forms of such wheels. tremely simple, being composed of only twoparts.

A contact wheel has a rubber or generally plastic rim, engaging eitherloose particles of an abrasive compound, or the inside of a coherentabrasive band. It is driven by a strong metal shaft engaging a more orless rigid hub.

' lt rotates at surface speeds of 5,000 to 10,000 feet per minute. ormore, against the resistance of the work piece. Centrifugal forces areapplied to the plastic rim in changing, regular and irregular patterns.tending to locally disrupt the contact between the rubber and itssupport, and in aggravated cases to destroy the rim and endangerpersonnel and property. It is known that such disruption can becounteracted and prevented by suitable, positive I anchorage of theplasticrim in the supporting material.

1 have designed a contact wheel of the traction type, adapted to engagethe inside of an abrasive band, with a rim and anchorage thereof, whichis particularly economical to make and elficient to use.

The efliciency of such a wheel depends on a number of features includingamong others the strength of its hub, the traction and workingcharacteristics of its rim, the firmness of the rim anchorage; also thedegreeto which the wheel is dynamically balanced to avoid vibrations,noise, chattering and heating up. Vibrations are produced at high speedsby nnsymmetrical distribution of mass about the center of rotation, evenif the wheel be statically balanced. The new wheel is greatly improvedin this respect. it can be safely and si'mplyproduced in such form thata simple test of static balance will practieally insure dynamic balanceeven at the most rapid speeds contemplated.

These and other advantages of the invention will be understood onconsideration of the detailed description of a preferred embodimentwhich follows, and which is illustrated in the schematic drawingappended hereto.

In the drawing, Figure 1 is a side view of'a contact.

wheel in accordance herewith, showing part of the plastic I molded of asuitable type of rubber.

v The body as shown comprises a circular flange 12, a central hub 13,and an intermediate web 14.

The outer surface of the flange 12 is generally cylindri cal but has aplurality of parallel circular grooves 15 deeply recessed into themetal. The cross-sectional contour of such grooves can be approximatelyrectangulan. Preferably the flange is roughened by additional, parallelIt is extion with a flat belt at high speeds.

rim, intersectthe larger grooves 15 in the flange 12. thereby forming aseries .of ports'l9 through which these grooves 15 communicate with theholes 17. A'se'ction of one such port 19 is shown in Figure 5, and theirarrangement in the flange 12 will beseen in Figure 3. The ports formsubstantially rectangular holes in theinner surfaces of the grooves 15if the cross-sections of the grooves are rectangular; the drill holesbeing circular.

The rubber rim 11, as shownin Figure 6, comprises an outer layer 20surrounding the flange 12, and bonded to the shallow grooves 16 by'vulcanizing. 0n the inside of layer 20 there are parallel peripheralribs 21, filling the deep grooves-'15. On the inside of these ribs thereare buttons 22, extending through the portholes l9 and expanding intoaxially extending holes 17. The layers 20, ribs 21, and buttons 22 forma homogeneous, coherent mass. The buttons 22 anchor the ribs 21, andthereby the covering layer 20 of the rubber rim 11, to the metal of theflange 12, againstcentrifugal forces tending to separate the coveringfrom the flange.

The outer surface of the rim. 11 is desirably crowned if the wheel isintended to engage an abrasive belt. Such crowning is practicallyrequired to maintain proper trac- The crowning is usually so slight thatit is barely noticeable on inspection of the wheel. The preferred outersurface also has serrations 23. I

Such serrations are most economically formed by a cutting operation uponthe crowned, molded rim surface. The exact pattern of such serrationsdepends on the type of material to be worked upon in the use of thecompleted wheel, and the fineness of finish desired for such material.In .the great majority of applications it is best to have suchserrations extend at an angle with the peripheral edges of the rim, asshown in Figure 3, thereby avoiding shock impacts. I generally make theworking edges of the serrations, at the outside surface of the rim, assharp-cornered aspossible; they will then act like files, even whenapplied through the base material of an abrasive belt driven by thewheel. Chattering marks onthe workpiece can be avoided by properinclination of such sharp-cornered edges with respect to the peripheralrim edges. The serrated wheel surface will usually promote the necessarydissipation of heat, and provide other advantages.

T he firm and uniform holding of the crowned, serrated, sharp-corneredplastic rim to the metal support at high speed rotation is one of theimportant requirements upon a contact wheel. Therefore an essentialfeature of the metal body 10 consists in the port holes 19 integrallyformed in, distributed over, and recessed into the flange 12, which areundercut below the surface of this flange by the holes 17, in order toprovide anchorage for the rubber buttons 22. The anchorage for thesebuttons, and thereby for the rubber ,or plastic rim in its entirety, isvital for the steady, quiet and safe performance of the wheel undercentrifugal load and added load imposed by the pressure of theworkpiece. Deep grooves 15 and intersecting drill holes 17 are essentialas they provide rectangular or similarlysharp-cornered openings andintersecting, inwardly expanding recesses in the mctaL'for Re. 24,152Reiuuod May 15, 1 956 llangc to a narrow web casting.

Figures 2 and 3): likewise, that the intersecting holes 17 are so spacedand intersected that the total area of the area and that said ports areclosely spaced from one another by approximately uniform distancesperipherally and laterally of the wheel. being arranged in a pluralityof circular rows intersected by transverse rows.

For convenience in forming such recesses I prefer machining the grooves15 as continuous holes. rather than coring or the like. Of coursecoring. machining and other processes can bccombined in somemanufacturing shops, suitably equipped.

.from the standpoint of dynamic balance and smooth,

quiet operation at high speeds. are produced by casting the metal in awide. unobstructed mold. 'Eflicieut hub, web and flange sections arethus produced. Both grooves l5 and holes 17 can-then be formed bymachining. When suehwheels are statically balanced pursuant to molding vand vulcaniiing on the rubber. they are dynamically bal anced also.without further test. They will run with a minimum of vibration. noise.chattering and heating up even at maximum speed.

This suppression of noise. chattering and heating up is a factorof theutmost importance, since it determines the attainable average speed ofthe manufacturing process in-.

volving the use of contact wheels. Therefore, it is an important featureof the present design that it allows the production of a trulyhomogeneous flange, which is dynamically balanced with a minimum ofdifficulty and a maximum of success. This is further promoted byextending the plastic rim 11 not only over the outer but also over theside surfaces of the flange. covering the outer ends of the drilledholes 17 and thereby eliminating screeching noises which are otherwiseproduced by highspecd rotation of the wheel. v

It is also desirable to make the wheel as light and strong as possible.Earlier designs of rubber-coated contact wheels for high speed haveprovided inwardly expanding anchorage by combining a plurality of metalparts into a built-up body; for instancc'by securing a wide perforatedIn order to obtain the necessary strong cohesions between the differentparts of such a built up wheel, local set screws, rivets, welds, shrinkfitting operations, or combinations thereof had to be used. It will beseen by persons skilled in the art.

upon consideration of the material and labor costs andv other pertinentfactors, that the present two part wheel provides a superior combinationof lightness, strength,

balance, and general economy.

Finally it will be seen, in the light ofthe present disresulting ports19 covers a major portion of said surface 1 I 4 closure. that variousmodification and improvementscan be applied to the preferred formschematically shown, within the scope of my present invention. Thisscope is defined by my claims. which follow. I I

I claim:

l. A contact wheel comprising an elastic rim of the traction type toengage successive portions of the inside of an abrasive band and todrive it against the resistance ofa workpiece pressed against theportion of the band in contact with the wheel; and a rigid body havingthe elastic rim molded thereon, the body consisting of a homogeneouscasting and comprising a flange whichhas a generally cylindrical outersurface with a plurality of closely spaced port holes uniformlydistributed over said.

entire surface'in a plurality of laterally spaced circular rowsintersecting with a plurality of pherip'hcrally spaced transverse rowsof such holes, the total area of such holes being a major part ofthearea of said outer surface, each 'port hole being recessed into andundercut below said outer surface and communicating with another surfaceof the flange. whereby the plastic rim molded thereon has closelyspaced. integral and homogeneous extensions laterally and peripherallydistributed over the flange and anchoring the rim to thefiaugc againstthe forces resulting from aid resistance of the workpiece and from asurface speed in therange of about 5000 to 10,000 feet per minute. '2'.A contactwheel according to claim 1, the rim of which'has an outersurface with serrations therein, said serrations being inclined withrespect to the peripheral edges of the rim and having sharp-corneredworking edges at the outside surface of the rim.

References Cited in the file'of this patent or the original patent v UNITED STATES PATENTS Bailey June 24, 186.2 58,027. Robbins Sept. ll,I866 ll0,098 Whitney Dec. 13, I870 .l70,-l78 Locke Nov. 23, 1875 626.016Model c July 4, I899 932,038 Maier Aug. 24, i909 t.t 10.804 Little Sept,15, I914 'l,l82,l(r2 Furbcr May 9, l9l6 1,438,098 Delzell a .d Dec. 5,I922 1.576.924 Malloy Mar. 16, [926 1,592,043 Noelting July 13, 19261682,899 Fletcher Sept. 4. I928 l,97l.653 Levoy et al Aug. 28, 19342,162,279 Hcrchenrider June 13, 1939 2.58l.270 McVey a"; Jan. 1, I952FORElGN PATENTS 520,439 Great Britain Apr. 24, 19.40

